What fed the subprime lending spree?

MARK AUSTIN THOMAS: Some experts are tying the crisis in subprime lending to the apparent abuse of a financial innovation. That innovation's called "securitization." It's the packaging of mortgage loans into salable securities. Marketplace's Steve Tripoli explains how securitization might have fed the subprime lending spree that's now unraveling in bad loans and corporate collapse.

STEVE TRIPOLI: Securitization greatly expands available credit. But it also off-loads risk.

Loan originators no longer hold the consequences of reckless lending. Investors believe that bundling risky loans makes them safer. Put the two together and the folks making the money are all looking the other way.

KEVIN BYERS: To the extent that that money is available in abundance for loans with looser underwriting guidelines, essentially giving borrowers enough rope to hang themselves with. Or, for that matter, giving people that are out to commit fraud the liquidity to do so. In the end, it's going to hurt the legitimate borrowers.

So does Byers think securitization may have triggered some subprime abuses?

BYERS: It funded it, so, you can follow the money. And in my business, that's how we get to our answers.

Some investors of course will be hurt. And regulators who'd been warned will have egg on their faces. But the bigger worry now is that all this will spill into the wider economy.